Walter Finch (Robin Williams) is revealed to be the girl's murderer. Ellie (Hilary Swank) figures this out from looking in one of Walter's books that Ellie had, and finding his autograph inside. She also finds the shell casing from the shot that killed Hap and puts everything together. Ellie goes to Walter's cabin to look for him, but she is met by a hail of gunfire. Will (Al Pacino) reveals to Rachel (Maura Tierney) that he was guilty of falsifying evidence by planting a drop of blood, and this was part of his guilty conscience. Still suffering the effects of sleep deprivation, he finds out Ellie went to the cabin, and drives after her. He hallucinates almost crashing into an imaginary truck. When he gets there, he tells Ellie to give him covering fire so he can get inside the cabin. Dodging a hail of gunfire, Will slips under the cabin and rushes inside. "You forgot the wild card, Will" says Walter, before shooting Will with a pistol. Will recoils from the shot and fires a shotgun blast, killing Walter and knocking him into the water, where he slowly sinks. Will, gravely injured, goes outside and lies down on the dock, confessing to Ellie that he shot his partner but he's not sure if it's an accident or on purpose any more. She takes out the shell casing that would incriminate him, and she tries to throw it into the lake. He grabs her arm and stops her. "Don't lose your way," says Will. He closes his eyes. "Let me sleep." Ellie calls for an ambulance, but it's already too late. Will Dormer dies lying on the dock, finally at rest.

In the scene on the ferry, when Williams and Pacino are talking, in the shots showing Williams, Pacino is facing the center of the ferry frequently, while immediately afterward in the shots showing Pacino, he is facing Williams again.